Giant 12-tonne box lowered into place for fusion upgrade

12-tonne ‘double beam box’ vessel will double MAST Upgrade’s heating power, allowing scientists to investigate plasma conditions needed for future power plants.
3 November 2026

Engineers at the UK Atomic Energy Authority (UKAEA) have achieved a technological milestone, having manoeuvred a massive 12-tonne component into position for the UK’s flagship fusion machine, MAST Upgrade, at UKAEA’s Culham Campus.

The double beam box will double the machine’s neutral beam heating power, helping researchers to investigate the technologies and physics needed for future fusion power plants.

A double beam box being installed by experts wearing protective clothing at UKAEA.
The 12-tonne double beam box vessel lifted into place for MAST Upgrade fusion machine, at UKAEA’s Culham Campus.
Read the full press release on GOV.UK